Add invariant config coverage test (#5779)

## Why
Ensure that all resource have invariant test coverage. Recent example
where lack of coverage caused to release a bug in migrate rewrite
#5775

Author: denik

acceptance/invariant_test.go

@@ -0,0 +1,137 @@
+package acceptance_test
+
+import (
+	"os"
+	"path/filepath"
+	"slices"
+	"strings"
+	"testing"
+
+	"github.com/databricks/cli/bundle/config"
+	"github.com/databricks/cli/libs/dyn"
+	"github.com/databricks/cli/libs/dyn/yamlloader"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+const invariantConfigsDir = "bundle/invariant/configs"
+
+// LackingInvariantTest lists keys from config.ResourcesTypes that knowingly lack
+// a covering config in invariantConfigsDir. Keys match the ResourcesTypes
+// form: "<group>" for the resource itself, "<group>.permissions" / "<group>.grants"
+// for permissions/grants coverage. Add a config and remove the entry to close a gap;
+// the test fails if an entry here is actually covered, so the list only shrinks.
+var LackingInvariantTest = map[string]bool{
+	"quality_monitors": true,
+
+	"alerts.permissions":            true,
+	"apps.permissions":              true,
+	"clusters.permissions":          true,
+	"dashboards.permissions":        true,
+	"experiments.permissions":       true,
+	"pipelines.permissions":         true,
+	"postgres_projects.permissions": true,
+	"sql_warehouses.permissions":    true,
+
+	"catalogs.grants":              true,
+	"external_locations.grants":    true,
+	"registered_models.grants":     true,
+	"vector_search_indexes.grants": true,
+	"volumes.grants":               true,
+}
+
+// TestInvariantConfigsCoverage ensures that the invariant test configs in
+// bundle/invariant/configs cover every bundle resource type, and that resource
+// types supporting permissions or grants have at least one config exercising them.
+//
+// config.ResourcesTypes is the source of truth: it maps each resource group
+// (e.g. "jobs") to its Go type and, where the resource struct has a Permissions
+// or Grants field, adds derived keys "<group>.permissions" and "<group>.grants".
+func TestInvariantConfigsCoverage(t *testing.T) {
+	present, withPermissions, withGrants := scanInvariantConfigs(t)
+
+	keys := make([]string, 0, len(config.ResourcesTypes))
+	for key := range config.ResourcesTypes {
+		keys = append(keys, key)
+	}
+	slices.Sort(keys)
+
+	for _, key := range keys {
+		var covered bool
+		var hint string
+		switch {
+		case strings.HasSuffix(key, ".permissions"):
+			group := strings.TrimSuffix(key, ".permissions")
+			covered = withPermissions[group]
+			hint = "attaches permissions to a " + group + " resource"
+		case strings.HasSuffix(key, ".grants"):
+			group := strings.TrimSuffix(key, ".grants")
+			covered = withGrants[group]
+			hint = "attaches grants to a " + group + " resource"
+		default:
+			covered = present[key]
+			hint = "defines a " + key + " resource"
+		}
+
+		if LackingInvariantTest[key] {
+			assert.False(t, covered,
+				"%q is covered by a config in %s; remove it from LackingInvariantTest", key, invariantConfigsDir)
+			continue
+		}
+		assert.True(t, covered,
+			"no config in %s %s; add one or allowlist %q", invariantConfigsDir, hint, key)
+	}
+}
+
+// scanInvariantConfigs parses every config in the invariant configs directory and
+// returns the set of resource groups present, the groups with at least one resource
+// carrying permissions, and the groups with at least one resource carrying grants.
+func scanInvariantConfigs(t *testing.T) (present, withPermissions, withGrants map[string]bool) {
+	present = map[string]bool{}
+	withPermissions = map[string]bool{}
+	withGrants = map[string]bool{}
+
+	entries, err := os.ReadDir(invariantConfigsDir)
+	require.NoError(t, err)
+
+	for _, entry := range entries {
+		if entry.IsDir() || !strings.HasSuffix(entry.Name(), ".yml.tmpl") {
+			continue
+		}
+		path := filepath.Join(invariantConfigsDir, entry.Name())
+		contents, err := os.ReadFile(path)
+		require.NoError(t, err)
+
+		v, err := yamlloader.LoadYAML(path, strings.NewReader(string(contents)))
+		require.NoError(t, err, "failed to parse %s", path)
+
+		resources := v.Get("resources")
+		if resources.Kind() != dyn.KindMap {
+			// Some configs (e.g. PyDABs) declare resources outside of YAML.
+			continue
+		}
+
+		for _, group := range resources.MustMap().Pairs() {
+			groupName := group.Key.MustString()
+			present[groupName] = true
+
+			if group.Value.Kind() != dyn.KindMap {
+				continue
+			}
+			for _, resource := range group.Value.MustMap().Pairs() {
+				cfg := resource.Value
+				if cfg.Kind() != dyn.KindMap {
+					continue
+				}
+				if cfg.Get("permissions").Kind() != dyn.KindInvalid {
+					withPermissions[groupName] = true
+				}
+				if cfg.Get("grants").Kind() != dyn.KindInvalid {
+					withGrants[groupName] = true
+				}
+			}
+		}
+	}
+
+	return present, withPermissions, withGrants
+}